Shutter for motion-picture machines



UNITED STATES HAROLD J. CHAPMAN, OF SPEED, KANSAS.

SHUTTER FOR MOTION-PICTURE MACHINES.

Specification of Letters Patent.

Patented Nov. 2, 1920.

Application filed November 11, 1919. Serial No. 337,338.

0 calico/10m it may concern Be it known that I, HAROLD J. CHAPMAN, citizen of the United States, residing at Speed, in the county of Phillips and State of Kansas, have invented certain new and useful Improvements in Shutters for hiotion- Picture li Iachines, of which the following is a specification.

This invention relates to an improved shutter for motion picture machines and has one of its principal objects to provide a shutter wherein the light rays will not be entirely out off during the period of occultation, thereby obviating the sharp contrast produced by completely darkening the screen between the periods of illumination thereof.

The invention has as a further object to provide a shutter wherein, while the light will not be entirely out off, still, shifting of the film will produce no visible effect upon the screen.

A still further object of the invention is to provide a shutter having means to intercept the light rays during each period of illumination for producing an effect on the screen tending to balance the effect produced by the interception of the light rays durin the intervening periods of occultation.

And the invention has as a still further object to provide a shutter which may be employed upon substantially any conventional type of motion picture machine.

Other and incidental objects will appear hereinafter.

In the drawings:

Figure 1 is a front elevation showing my improved shutter in connection with a motion picture machine which is more or less diagrammatically illustrated, and

Fig. 2 is a horizontal section taken through the shutter.

Referring now more particularly to the drawings I have, for convenience, shown my improved shutter in connection with a mo tion picture projecting machine 10 of conventional type, this machine being provided with the usual shaft 11 for carrying the shutter. In carrying the invention into effect, my improved shutter is formed with a. hub 12 adapted to fit over the shaft 11 and provided with a suitable set screw 13 by which the hub may be fixed to the shaft. Projecting radially from the hub is a hub ring or disk 14 which may be formed integral with the hub or otherwise secured thereto and surrounding the hub disk in concentric relation is the rim 15 of the shutter. Supporting the rim with respect to the hub disk are oppositely disposed segmental wings or interrupter respectively indicated as a whoic by the reference numerals 16 and 17. As will be perceived, these wings are each made up of a plurality of spaced radial spokes or slats extending between the periphery of the hub disk and the inner face of the rim and, if desired, the hub disk, spokes and rim may be formed as an integral structure. However, if preferred, the spokes may be attached to the hub disk and rim respectively. As particularly brought out in Fig. l, the wings are of equal area or, in other words, are like segments. The wing 16 is designed to intercept the light rays during each period of occultation and for this reason the spokes of said wing are spaced closer together than are the spokes of the wing 17. However, it will be noted that the wing 16 will not entirely out 0d the light rays to cause a complete darkening of the screen but, on the other hand, sufficient light will shine between the spokes of the wing to partially illuminate the screen during each period of occultation. The sharp contrast produced on the screen by completely cutting off the light rays during each period of occultation will thus be eliminated. Nevertheless, the spokes of the wing 16 will, due to the speed of rotation of the shutter, intercept the light sufficiently to prevent any visible effect on the screen of the shifting of the film. The wing 17 is designed to partially intercept the light durin g each period of illumination of the screen and the spokes of this wing are accordingly spaced relatively wide apart. As will be appreciated, the wing 17, in intercepting the light rays during each period of illumination, will tend to produce an effect on the screen acting to counterbalance the effect produced by the darkening of the screen during each period of occultation. quently, this wing 17 will tend to eliminate the common fault of flickering and, of course, the effect produced by this'latter wing may be varied by varying the spacing of the spokes of the wing. In like manner, the darkening effect produced by the wing 16 may be varied by varying the spacing of the spokes of this wing. Further, in practi- Consecal use'it be found expedient to increase the size of one wing and reduce the size of the other or to make the spokes of the Wings either longer or shorter. All such details of practical installation are, of course, comprehended Within the spirit of the present invention.

Having thus described the invention What is claimed as new is:

1. In a shutter of the character described, the combination of a hub spaced slats extending from the hub to form an interrupter, and a second interrupter extending from the 1 ,samas 

